The Consumer Price Index (CPI) in any year is the cost in that year of a bundle of goods and services purchased by a typical urban consumer compared to the cost of that bundle of goods and services in a base period. For this series, the base period is the 1982-84 annual average. The series extends the Bureau of Labor Statistics CPI-U (consumer price index for all urban consumers) series back in time. The “official” CPI series published by the begins in 1913 and is reported monthly.  The annual data we report are the average of the 12 months of observations.  Improvements to the official series have been made here; thus the CPI series here is identical to the BLS series only from 1978 onward.

Although the CPI may be the most popular and best-known price series, any CPI series is beset with limitations. A long-run series, such as the one presented here, has these limitations magnified, and also has difficulties of its own. Among these problems are: (1) The CPI pertains only to commodities purchased by consumers; it is not a price index of all production or all consumption in the economy. (2) It is difficult to account for changing qualities of commodities and introduction of new commodities over time. (3) A CPI is only as good as the basic price and weight (expenditure) data. In general, these data are less available and of lower quality as one goes further into the past.

“The MeasuringWorth web site provides by far the best measure of the history of U.S. consumer prices all the way back to 1774. Where alternative measures are available for particular historical intervals, MeasuringWorth has chosen the series that best reflect decades of price research. Other web sites are in part based on price series that were developed fifty or more years ago and do not reflect the consensus of modern research.”
Robert J Gordon, Stanley G. Harris Professor in the Social Sciences, Northwestern University, Distinguished Fellow of the American Economic Association, Member of the NBER Business Cycle Dating Committee.

For a further discussion of the limitations of the CPI, and for a detailed exposition of the development of this CPI series, please read What Was the Consumer Price Index Then? A Data Study (349K PDF).

Please read our Note on Data Revisions.

Lawrence H. Officer and Samuel H. Williamson, "The Annual Consumer Price Index for the United States, 1774-Present," MeasuringWorth, .
URL: http://www.measuringworth.com/uscpi/

Please let us know if and how this discussion has assisted you in using our calculators.